This invention relates to an apparatus for feeding a tape having label patterns previously printed thereon to a cutting machine operating at a constant speed.
It is easy to manufacture apparatus for unwinding a roll of tape and for feeding the tape a constant speed for subsequent printing or cutting. Such a purpose can be achieved simply by drawing the tape by means of a constantly rotating drum or the like.
However, when a tape has a series of identical patterns previously printed thereon, for example, label patterns L as shown in FIG. 5, it is inadequate to draw the tape at a constant speed in order to feed the tape to a cutting or re-printing machine operating at a constant speed. If a tape is fed at a constant speed to a cutting machine operating at a constant speed, the tape is cut into pieces of the same length. However, the patterns printed on the tape are not exactly the same in length. As illustrated in FIG. 5, the length l.sub.1 of an upstream label pattern L and the length l.sub.2 of a downstream label pattern L positioned remotely from the former can possibly be somewhat different because of many factors including the accumulation of slight misalignment of the patterns on the tape during printing, the stretch of tape during high-speed feeding under high tension, the influence of humidity during feeding, the influence of humidity and aging during storage in the form of a roll, slippage occurring upon drawing out, the resistance of the roll being unwound, and the like.
For this reason, drawing and cutting the tape at a given length will result in the incremental misalignment of the actual cutting line from the desired cutting line between adjoining printed patterns, failing to cut the tape into pieces each having one complete pattern and useful as labels.
It is, therefore, an object of the present invention to provide a tape feeding apparatus capable of feeding a tape having patterns printed thereon to a constantly operating machine like a cutter at a controlled high speed such that the machine may receive the tape in a manner such that the patterns are exactly positioned with respect thereto.
It is another object of the present invention to provide a versatile tape feeding apparatus capable of handling a variety of tapes having printed patterns of different lengths or widths with minimal replacement of parts.